This application describes a four-year project to study the relationship dynamics that contribute to risk for HIV transmission among male-to-female transgender women and their primary male partners. The goal of this research is to test a conceptual framework that contextualizes HIV risk within relationship dynamics, which can produce findings leading to the development of a theory-driven, culturally appropriate relationship-focused HIV prevention intervention for transgender women and their male partners. These communities are among the groups at highest risk for HIV infection in the United States. Our working conceptual model of relationship-level HIV risk emphasizes the contributions of gender roles, power dynamics, couples' communication, agreements about sex outside of the relationship, social and community support, and stigma. Deriving from this framework, we hypothesize that HIV risk for partners in a relationship arises out of both individual-level factors and dyadic-level factors, including discrepancies and disagreements between partners on health-related attitudinal and behavioral domains. We will address these aims using qualitative and quantitative methodologies, involving in-depth individual interviews with 20 couples and cross-sectional surveys with 200 couples. We propose innovative statistical techniques to examine our hypothesized effects. Findings from this research will be used to guide the development of an HIV prevention intervention for this unique relationship dyad, and will expand theoretical understanding of HIV risk within primary relationships. Public health impact: This project has the potential to improve understanding of relationship factors contributing to HIV risk among transgender women and their male partners, which will allow health professionals to intervene more effectively with these groups. Findings will contribute toward developing a theory-driven, culturally appropriate relationship-focused HIV prevention intervention with these groups. [unreadable] [unreadable] [unreadable] [unreadable]